We take a trip through the human head this week with scientist, philosopher and poet, Raymond Tallis. He thinks the brain gets too much of the attention whenever people talk abut the head and his new book, The Kingdom of Infinite Space, aims to put the story straight. Be warned: it's a story of vomiting, mucus, baldness, snogging and smoking. You can listen to our extended conversation with Prof Tallis as this week's Science Extra podcast.

The European Space Agency has published its call for a new generation of astronauts to go on missions to the International Space Station and, possibly, join Nasa on the moon in 2020. Guardian science correspondent Ian Sample talks to some hopeful spacefarers. Oh, and if you want to apply, you can find more information here. Let us know if you do...

We talk to Anantha Chandrakasan, director of the microsystems technology lab at the Massachusetts Institute of Technology, whose team has developed a computer chip that is ten times more efficient than any in use today. He explains why the future health of our planet depends on this type of low-power computer chip.